I don't understand this thread. It's like saying water is wet. It seems so obvious and so predictable that there's no point in explaining or saying it.
The casinos are the winners, and do you know where you find that? From the constantly increasing number of casinos in the world and on the forum. If it weren't profitable, there wouldn't be so many casinos.
There is absolutely nothing to be confused about in the thread, the Op could be little skeptical about how casino's makes their profits if players have to win regarded that as many players is how many they could win that maybe at the lost of the casino's but I think such thought should had been expected from one who does not have single ideal about the high chances for those players to loose while winning may be of luck since the casino's outcome is determined by the RNG.
Definitely, some user doesn’t know what is the house edge or how the house edge works which is why some user still doesn’t know that casino earn through this edge.
But we can’t blame either the user comment since most of the user on gambling discussion board knows well how profitable the casino is so a discussion like this already obvious.